The security of computing resources and associated data is of high importance in many contexts. As an example, organizations often utilize networks of computing devices to provide a robust set of services to their users. Networks often span multiple geographic boundaries and often connect with other networks. An organization, for example, may support its operations using both internal networks of computing resources and computing resources managed by others. Computers of the organization, for instance, may communicate with computers of other organizations to access and/or provide data while using services of another organization. In many instances, organizations configure and operate remote networks using hardware managed by other organizations, thereby reducing infrastructure costs and achieving other advantages. With such configurations of computing resources, ensuring that access to the resources and the data they hold is secure can be challenging, especially as the size and complexity of such configurations grow. In some instances, malicious behavior attempting to gain unauthorized access to computing resources includes the submission of requests made pursuant to unauthorized executable code, such as code that was authored for the purpose of attempting unauthorized access or by authorized code that has been infected and, as a result, has become modified. Detecting and preventing such unauthorized access is a complex undertaking, especially when data is stored throughout a distributed system.